The present invention relates to devices having a sensor adapted to measure the volume of a body cavity, such as a bladder, and to provide a signal to the user, wearer, or caregiver when the body cavity volume reaches a pre-determined threshold.
Today, devices adapted to measure bladder volume are widely used for diagnostic purposes in the medical profession, such as the urology field. Additionally, bladder volume measurement devices have been developed for continence training applications. Some of these devices provide a complete two or three-dimensional image of the bladder using ultrasonic transducers that are rotated or moved in a pattern within an ultrasound scanning head. These devices have the disadvantage of being large, heavy, complex and extremely costly and require significant signal processing and analysis capability. Another approach provides measures of bladder volume via arrays of ultrasonic transducers positioned on a subject""s body in an area or pattern in proximity to the bladder (e.g., around the waist of the wearer). In such devices, the array determines a number of points on the front and back walls of the bladder and fits a curve to the points to define a cross-section. This approach has the limitation of requiring significant computational resources due to the need for the complex curve-fitting analysis of the transducer data. Yet another approach involves the use of a single ultrasonic transducer positioned on the wearer""s abdomen in proximity to the bladder. In this device, an ultrasound pulse is transmitted to and through the bladder and the volume is calculated by comparing the time difference of the echoes from the front and rear walls of the bladder, A key disadvantage of this device is the difficulty in aiming the ultrasonic transducer at the bladder (i.e., the aim varies depending on application of the device). The entire device must be reapplied or shifted on the wearer to correct a non-optimal initial aim. Additionally, none of the known bladder volume measurement devices are easily or comfortably wearable by the subject.
Accordingly, it would be advantageous to provide a body cavity volume monitor which is comfortable to wear. It would also be advantageous to provide a body cavity volume monitor which can be adjusted to improve performance after the device is applied to the wearer. Further, it would be advantageous to provide a body cavity volume monitor which is configured such that even if it is displaced or not optimally aligned, an accurate measurement can be obtained.
In order to resolve the shortcomings of the prior art, the present invention provides a device or article which includes a base, a sensor adapted to detect when a body cavity of the wearer reaches a predetermined volume and a signal mechanism. The sensor is moveably mounted on the base so as to facilitate aiming of the sensor toward the body cavity. The signal mechanism is adapted to provide a signal to a wearer, a caregiver or an element of the article once the predetermined body cavity volume is reached.
In an alternative embodiment, the present invention provides a device adapted to measure the volume of a body cavity comprising a first sensor and a second sensor. The first sensor has a first orientation toward the body cavity and is adapted to measure a first distance between the front wall and the back wall of the body cavity. The second sensor has a second orientation toward the body cavity which is different from the first orientation and is adapted to measure a second distance between the front wall and the back wall of the body cavity. The device also includes a signal mechanism which provides a signal to a wearer or a caregiver once a predetermined volume of the body cavity is reached, wherein the predetermined volume is calculated based on the greater of the first and second distances between the front wall and the back wall of the body cavity.